Data sending method and apparatus

ABSTRACT

A data transmission method and an apparatus are provided. The method includes: determining, by a base station, a time-domain interval of available time-frequency resources in an unlicensed spectrum, where the available time-frequency resources are continuous time-frequency resources in a time domain; sending, by the base station, a preamble signal in a first subframe in the interval, where the first subframe is an initial subframe in the interval; and sending, by the base station, downlink control information and data after sending the preamble signal, where the data is in the first subframe, the downlink control information includes scheduling indication information, and the scheduling indication information is used to indicate a frequency-domain location of the data. According to the present invention, spectrum utilization can be improved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2014/090650, filed on Nov. 7, 2014, the disclosure of which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

Embodiments of the present invention relate to a communications system,and in particular, to a data sending method and an apparatus.

BACKGROUND

A spectrum in which a serving cell of a Long Term Evolution (LTE) systemis located is a licensed spectrum, and can be used by only an operatornetwork with the purchased licensed spectrum. At present, the industryincreasingly concerns an unlicensed spectrum. Carrier aggregation isperformed on an unlicensed spectrum that is used as a secondary carrierand a licensed spectrum that is used as a primary carrier, to serve userequipment (UE). This is the most concerned method for using anunlicensed spectrum at present. The secondary carrier corresponding tothe unlicensed spectrum may be referred to as an unlicensed secondarycarrier, and the primary carrier corresponding to the licensed spectrummay be referred to as a licensed primary carrier.

The unlicensed spectrum may be used as the secondary carrier to transmitdata for UE. However, the unlicensed spectrum may be discontinuous. Abase station can only use the unlicensed spectrum for a specific timeperiod after obtaining a resource of the unlicensed spectrum by means ofcontending. After another base station occupies the unlicensed spectrumby means of contending, when the another base station occupies theunlicensed spectrum, the base station cannot send a signal by using theunlicensed spectrum. The base station cannot send a signal to UE byexclusively using the unlicensed spectrum. Therefore, the unlicensedspectrum can be used only as a secondary carrier to provide a servicefor user equipment. The unlicensed spectrum needs to be anchored to alicensed spectrum for using. For example, the unlicensed secondarycarrier needs to be anchored to a licensed primary carrier for using. Inthis case, the primary carrier and the secondary carrier need to have asame timing relationship, a same subframe number, and a same subframeboundary.

The unlicensed spectrum refers to a public spectrum that anyorganization or person can use. However, a specific rule needs to befollowed in use, for example, listen before talk (LBT). That is, onlywhen it is determined, by means of listening, that the spectrum is idle,a signal can be sent on the unlicensed spectrum. Generally, clearchannel assessment (CCA) or extended CCA (ECCA) is used in LBT. Achannel is listened for at least 20 μs for a base station in CCA. If asignal is not obtained by means of listening, the channel is consideredto be idle and can be used. If the base station finds, after performinglistening for 20 μs, that the channel is occupied, CCA is switched toECCA. A random number R is generated for the base station in ECCA, andthe channel is listened in continuous R time periods. If the channel isall in an idle state in the R time periods, the channel can be used. Anend time of CCA or ECCA may be a symbol at the middle of a subframe ofthe unlicensed spectrum. Therefore, data cannot be transmitted atsubsequent several symbols. This causes a waste of spectrum resources.

SUMMARY

Embodiments of the present invention provide a data sending method andan apparatus, so as to improve spectrum utilization.

According to a first aspect, a data sending method is provided,including: determining, by a base station, a time-domain interval ofavailable time-frequency resources in an unlicensed spectrum, where theavailable time-frequency resources are continuous time-frequencyresources in a time domain; sending, by the base station, a preamblesignal in a first subframe in the interval, where the first subframe isan initial subframe in the interval; and sending, by the base station,downlink control information and data after sending the preamble signal,where the data is in the first subframe, the downlink controlinformation includes scheduling indication information, and thescheduling indication information is used to indicate a frequency-domainlocation of the data.

In a first possible implementation manner, the downlink controlinformation is in a downlink control channel, and the first subframeincludes N symbols in the time domain, where the downlink controlchannel is located in n symbols following the preamble signal; or thedownlink control channel is located in last n symbols of the firstsubframe; or the downlink control channel is an enhanced physicaldownlink control channel, the enhanced physical downlink control channelis located in the subframe in which the preamble signal is located, andthe enhanced physical downlink control channel is located in a symbolafter the preamble signal; where 0<n<N, and both n and N are naturalnumbers.

With reference to the first possible implementation manner, in a secondpossible implementation manner, when the downlink control channel islocated in the n symbols following the preamble signal, the data is in asymbol after the downlink control channel; when the downlink controlchannel is located in the last n symbols of the first subframe, the datais in a symbol between the preamble signal and the downlink controlchannel; or when the downlink control channel is the enhanced physicaldownlink control channel, the data is in a symbol after the preamblesignal.

With reference to the first possible implementation manner, in a thirdpossible implementation manner, the downlink control information furtherincludes location indication information, and the location indicationinformation is used to indicate a start symbol m of the data in thefirst subframe in the time domain, where when the downlink controlchannel is located in the n symbols following the preamble signal, thedata is between the symbol m and a last symbol of the first subframe; orwhen the downlink control channel is located in the last n symbols ofthe subframe in which the preamble signal is located, the data isbetween the symbol m and a symbol before the downlink control channel.

With reference to the first to the third possible implementationmanners, in a fourth possible implementation manner, the preamble signalis in at least one symbol at the beginning of the interval.

With reference to any one of the first aspect or the first to the fourthpossible implementation manners, in a fifth possible implementationmanner, the downlink control information further includes durationindication information, and the duration indication information is usedto indicate available duration of the base station in the unlicensedspectrum.

With reference to the fifth possible implementation manner, in a sixthpossible implementation manner, the downlink control informationincludes first downlink control information and second downlink controlinformation, the scheduling indication information is in the firstdownlink control information, the duration indication information is inthe second downlink control information, the first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

With reference to any one of the first aspect or the first to the sixthpossible implementation manners, in a seventh possible implementationmanner, the preamble signal is used to indicate the available durationin the unlicensed spectrum, and the available duration is a length ofthe time-domain interval of the available time-frequency resources.

With reference to the seventh possible implementation manner, in aneighth possible implementation manner, at least two different preamblesignals indicate different duration.

With reference to any one of the sixth to the eighth possibleimplementation manners, in a ninth possible implementation manner, themethod further includes: sending, by the base station in n symbols atthe beginning of a second subframe, the downlink control channel onwhich the first subframe is scheduled, where the second subframe is inthe duration and is after the first subframe.

With reference to any one of the first aspect or the first to the ninthpossible implementation manners, in a tenth possible implementationmanner, the preamble signal occupies fixed duration in the time domain.

With reference to any one of the first aspect or the first to the tenthpossible implementation manners, in an eleventh possible implementationmanner, the preamble signal is a sequence in at least one presetsequence.

According to a second aspect, a base station is provided, including: aprocessing unit, configured to determine a time-domain interval ofavailable time-frequency resources in an unlicensed spectrum, where theavailable time-frequency resources are continuous time-frequencyresources in a time domain; and a sending unit, configured to send apreamble signal in a first subframe in the interval, where the firstsubframe is an initial subframe in the interval, where the sending unitis further configured to send downlink control information and dataafter sending the preamble signal, where the data is in the firstsubframe, the downlink control information includes schedulingindication information, and the scheduling indication information isused to indicate a frequency-domain location of the data.

In a first possible implementation manner, the downlink controlinformation is in a downlink control channel, and the first subframeincludes N symbols in the time domain, where the downlink controlchannel is located in n symbols following the preamble signal; or thedownlink control channel is located in last n symbols of the firstsubframe; or the downlink control channel is an enhanced physicaldownlink control channel, the enhanced physical downlink control channelis located in the subframe in which the preamble signal is located, andthe enhanced physical downlink control channel is located in a symbolafter the preamble signal; where 0<n<N, and both n and N are naturalnumbers.

With reference to the first possible implementation manner, in a secondpossible implementation manner, when the downlink control channel islocated in the n symbols following the preamble signal, the data is in asymbol after the downlink control channel; when the downlink controlchannel is located in the last n symbols of the first subframe, the datais in a symbol between the preamble signal and the downlink controlchannel; or when the downlink control channel is the enhanced physicaldownlink control channel, the data is in a symbol after the preamblesignal.

With reference to the first possible implementation manner, in a thirdpossible implementation manner, the downlink control information furtherincludes location indication information, and the location indicationinformation is used to indicate a start symbol m of the data in thefirst subframe in the time domain, where when the downlink controlchannel is located in the n symbols following the preamble signal, thedata is between the symbol m and a last symbol of the first subframe; orwhen the downlink control channel is located in the last n symbols ofthe subframe in which the preamble signal is located, the data isbetween the symbol m and a symbol before the downlink control channel.

With reference to the first to the third possible implementationmanners, in a fourth possible implementation manner, the preamble signalis in at least one symbol at the beginning of the interval.

With reference to any one of the second aspect or the first to thefourth possible implementation manners, in a fifth possibleimplementation manner, the downlink control information further includesduration indication information, and the duration indication informationis used to indicate available duration of the base station in theunlicensed spectrum.

With reference to the fifth possible implementation manner, in a sixthpossible implementation manner, the downlink control informationincludes first downlink control information and second downlink controlinformation, the scheduling indication information is in the firstdownlink control information, the duration indication information is inthe second downlink control information, the first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

With reference to any one of the second aspect or the first to the sixthpossible implementation manners, in a seventh possible implementationmanner, the preamble signal is used to indicate the available durationof the base station in the unlicensed spectrum, and at least twodifferent preamble signals are corresponding to different duration.

With reference to the seventh possible implementation manner, in aneighth possible implementation manner, at least two different preamblesignals indicate different duration.

With reference to any one of the sixth to the eighth possibleimplementation manners, in a ninth possible implementation manner, thesending unit is further configured to send, in n symbols at thebeginning of a second subframe, the downlink control channel on whichthe first subframe is scheduled, where the second subframe is in theduration and is after the first subframe.

With reference to any one of the second aspect or the first to the ninthpossible implementation manners, in a tenth possible implementationmanner, the preamble signal occupies fixed duration in the time domain.

With reference to any one of the second aspect or the first to the tenthpossible implementation manners, in an eleventh possible implementationmanner, the preamble signal sent by the sending unit is a sequence in atleast one preset sequence.

According to a third aspect, a data sending method is provided,including: determining, by a base station, a time-domain interval ofavailable time-frequency resources in an unlicensed spectrum, where theavailable time-frequency resources are continuous time-frequencyresources in a time domain; and sending, by the base station, downlinkcontrol information and data, where the data is in a first subframe, thefirst subframe is an initial subframe in the interval, the downlinkcontrol information is in a downlink control channel, the downlinkcontrol information includes scheduling indication information andlocation indication information, the scheduling indication informationis used to indicate a frequency-domain location of the data, and thelocation indication information is used to indicate a time-domainlocation of the data.

In a first possible implementation manner, the first subframe includes Nsymbols in the time domain, where the downlink control channel islocated in n symbols at the beginning of a second subframe, and thelocation indication information is further used to indicate that thefirst subframe is a subframe before the second subframe; or the downlinkcontrol channel is located in last n symbols of the first subframe;where 0<n<N, and both n and N are natural numbers.

With reference to the first possible implementation manner, in a secondpossible implementation manner, the location indication information isused to indicate a start symbol m of the data in the first subframe inthe time domain, and when the downlink control channel is located in then symbols at the beginning of the second subframe, the data in the firstsubframe is between the symbol m and a last symbol of the firstsubframe; or when the downlink control channel is located in the last nsymbols of the first subframe, the data in the first subframe is afterthe symbol m and is before the downlink control channel.

With reference to any one of the third aspect, the first possibleimplementation manner, or the second possible implementation manner, ina third possible implementation manner, the downlink control informationfurther includes duration indication information, and the durationindication information is used to indicate available duration of thebase station in the unlicensed spectrum.

With reference to the third possible implementation manner, in a fourthpossible implementation manner, the downlink control informationincludes first downlink control information and second downlink controlinformation, the scheduling indication information is in the firstdownlink control information, the duration indication information is inthe second downlink control information, the first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

With reference to the third possible implementation manner or the fourthpossible implementation manner, in a fifth possible implementationmanner, the method further includes: sending, by the base station in then symbols at the beginning of the second subframe, the downlink controlchannel on which the first subframe is scheduled, where the secondsubframe is in the duration and is after the first subframe.

According to a fourth aspect, a base station is provided, including: aprocessing unit, configured to determine a time-domain interval ofavailable time-frequency resources in an unlicensed spectrum, where theavailable time-frequency resources are continuous time-frequencyresources in a time domain; and a sending unit, configured to senddownlink control information and data, where the data is in a firstsubframe, the first subframe is an initial subframe in the interval, thedownlink control information is in a downlink control channel, thedownlink control information includes scheduling indication informationand location indication information, the scheduling indicationinformation is used to indicate a frequency-domain location of the data,and the location indication information is used to indicate atime-domain location of the data.

In a first possible implementation manner, the first subframe includes Nsymbols in the time domain, where the downlink control channel islocated in n symbols at the beginning of a second subframe, and thelocation indication information is further used to indicate that thefirst subframe is a subframe before the second subframe; or the downlinkcontrol channel is located in last n symbols of the first subframe;where 0<n<N, and both n and N are natural numbers.

With reference to the first possible implementation manner, in a secondpossible implementation manner, the location indication information isused to indicate a start symbol m of the data in the first subframe inthe time domain, and when the downlink control channel is located in then symbols at the beginning of the second subframe, the data in the firstsubframe is between the symbol m and a last symbol of the firstsubframe; or when the downlink control channel is located in the last nsymbols of the first subframe, the data in the first subframe is afterthe symbol m and is before the downlink control channel.

With reference to any one of the fourth aspect, the first possibleimplementation manner, or the second possible implementation manner, ina third possible implementation manner, the downlink control informationfurther includes duration indication information, and the durationindication information is used to indicate available duration of thebase station in the unlicensed spectrum.

With reference to the third possible implementation manner, in a fourthpossible implementation manner, the downlink control informationincludes first downlink control information and second downlink controlinformation, the scheduling indication information is in the firstdownlink control information, the duration indication information is inthe second downlink control information, the first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

With reference to the third or the fourth possible implementationmanner, in a fifth possible implementation manner, the sending unit isfurther configured to send, in the n symbols at the beginning of thesecond subframe, the downlink control channel on which the firstsubframe is scheduled, where the second subframe is in the duration andis after the first subframe.

According to a fifth aspect, a data receiving method is provided,including: performing, by user equipment, detection on a downlinkcontrol channel to obtain downlink control information, where thedownlink control information includes scheduling indication information,and the scheduling indication information is used to indicate afrequency-domain location of scheduled data in a first subframe;determining, by the user equipment, a time-domain location of the datain the first subframe according to location indication information inthe downlink control channel or a preamble signal received in anunlicensed spectrum before the downlink control channel, where thelocation indication information is used to indicate the time-domainlocation of the data in the first subframe; and receiving, by the userequipment, the data in the unlicensed spectrum according to thefrequency-domain location and the time-domain location of the data.

In a first possible implementation manner, before the performing, byuser equipment, detection on a downlink control channel to obtaindownlink control information, the method further includes: receiving, bythe user equipment, the preamble signal in the unlicensed spectrum,where the preamble signal is a sequence in at least one preset sequence.

With reference to the first possible implementation manner, in a secondpossible implementation manner, before the performing, by userequipment, detection on a downlink control channel to obtain downlinkcontrol information, the method further includes: after receiving thepreamble signal, determining, by the user equipment, a location of thedownlink control channel in the unlicensed spectrum according to thepreamble signal.

With reference to the second possible implementation manner, in a thirdpossible implementation manner, the subframe includes N symbols in thetime domain, and the downlink control channel is located in n symbolsfollowing the preamble signal; or the downlink control channel islocated in last n symbols of a subframe in which the preamble signal islocated; or the downlink control channel is an enhanced physicaldownlink control channel, the enhanced physical downlink control channelis located in a subframe in which the preamble signal is located, andthe enhanced physical downlink control channel is located in a symbolafter the preamble signal; where the first subframe is the subframe inwhich the preamble signal is located, 0<n<N, and both n and N arenatural numbers.

With reference to the third possible implementation manner, in a fourthpossible implementation manner, the determining, by the user equipment,a time-domain location of the data in the first subframe according to apreamble signal received before the downlink control channel includes:determining, by the user equipment, a symbol in which the preamblesignal is located; and determining, by the user equipment according tothe symbol in which the preamble signal is located and a symbol in whichthe downlink control channel is located, a symbol in which the data inthe first subframe is located.

With reference to the third possible implementation manner, in a fifthpossible implementation manner, the location indication information isused to indicate a start symbol m of the data in the first subframe inthe time domain, and the determining, by the user equipment, atime-domain location of the data in the first subframe according tolocation indication information in the downlink control channelincludes: when the downlink control channel is located in the n symbolsfollowing the preamble signal, determining, by the user equipment, thatthe data in the first subframe is between the symbol m and a last symbolof the first subframe; or when the downlink control channel is locatedin the last n symbols of the subframe in which the preamble signal islocated, determining, by the user equipment, that the data in the firstsubframe is between the symbol m and a symbol before the downlinkcontrol channel.

In a sixth possible implementation manner, the downlink control channelis located in last n symbols of a detected subframe, and the firstsubframe is a subframe in which the downlink control channel is located.

In a seventh possible implementation manner, the performing, by userequipment, detection on a downlink control channel to obtain downlinkcontrol information includes: performing, by the user equipment,detection on a first downlink control channel and a second downlinkcontrol channel, where the first downlink control channel is located inn symbols at the beginning of a detected subframe, and the seconddownlink control channel is located in last n symbols of the detectedsubframe, and if the downlink control information is obtained in thesecond downlink control channel, the downlink control informationincludes the scheduling indication information, and the first subframeis a subframe in which the downlink control channel is located.

With reference to the sixth or the seventh possible implementationmanner, in an eighth possible implementation manner, the locationindication information is used to indicate a start symbol m of the datain the first subframe in the time domain, and the determining, by theuser equipment, a time-domain location of the data in the first subframeaccording to location indication information in the downlink controlchannel includes: determining, by the user equipment, that the data inthe first subframe is between the symbol m and a symbol before thedownlink control channel.

In a ninth possible implementation manner, the performing, by userequipment, detection on a downlink control channel to obtain downlinkcontrol information includes: performing, by the user equipment,detection on the downlink control channel to obtain the downlink controlinformation, where the downlink control channel is located in n symbolsat the beginning of a detected subframe; and when the downlink controlinformation includes the location indication information, determining,by the user equipment, that the first subframe is a subframe before asubframe in which the downlink control channel is located.

With reference to the ninth possible implementation manner, in a tenthpossible implementation manner, the location indication information isused to indicate a start symbol m of the data in the first subframe inthe time domain, and the determining, by the user equipment, atime-domain location of the data in the first subframe according tolocation indication information in the downlink control channelincludes: determining, by the user equipment, that the data in the firstsubframe is between the symbol m and a last symbol of the firstsubframe.

With reference to any one of the fifth aspect or the first to the tenthpossible implementation manners, in an eleventh possible implementationmanner, the downlink control information further includes durationindication information, and the duration indication information is usedto indicate available duration of a base station in the unlicensedspectrum.

With reference to the eleventh possible implementation manner, in atwelfth possible implementation manner, the downlink control informationincludes first downlink control information and second downlink controlinformation, the scheduling indication information is in the firstdownlink control information, the duration indication information is inthe second downlink control information, the first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

With reference to any one of the fifth aspect or the first to the fifthpossible implementation manners, in a thirteenth possible implementationmanner, the preamble signal is used to indicate available duration of abase station in the unlicensed spectrum, and at least two differentpreamble signals are corresponding to different duration.

With reference to any one of the eleventh to the thirteenth possibleimplementation manners, in a fourteenth possible implementation manner,the method further includes: performing, by the user equipment in nsymbols at the beginning of a second subframe, detection on the downlinkcontrol channel on which the second subframe is scheduled, where thesecond subframe is in the duration and is after the first subframe.

With reference to any one of the fifth aspect or the first to thefourteenth possible implementation manners, in a fifteenth possibleimplementation manner, the preamble signal occupies fixed duration inthe time domain.

According to a sixth aspect, user equipment is provided, including: aprocessing unit, configured to perform detection on a downlink controlchannel to obtain downlink control information, where the downlinkcontrol information includes scheduling indication information, and thescheduling indication information is used to indicate a frequency-domainlocation of scheduled data in a first subframe, where the processingunit is further configured to determine a time-domain location of thedata in the first subframe according to location indication informationin the downlink control channel or a preamble signal received in anunlicensed spectrum before the downlink control channel, where thelocation indication information is used to indicate the time-domainlocation of the data in the first subframe; and a receiving unit,configured to receive the data in the unlicensed spectrum according tothe frequency-domain location and the time-domain location of the data.

In a first possible implementation manner, before the processing unitperforms detection on the downlink control channel to obtain thedownlink control information, the receiving unit further includes:receive the preamble signal in the unlicensed spectrum, where thepreamble signal is a sequence in at least one preset sequence.

With reference to the first possible implementation manner, in a secondpossible implementation manner, before the processing unit performsdetection on the downlink control channel to obtain the downlink controlinformation, the processing unit further includes: after receiving thepreamble signal, determine, by the processing unit, a location of thedownlink control channel in the unlicensed spectrum according to thepreamble signal.

With reference to the second possible implementation manner, in a thirdpossible implementation manner, the subframe includes N symbols in thetime domain, and the downlink control channel is located in n symbolsfollowing the preamble signal; or the downlink control channel islocated in last n symbols of a subframe in which the preamble signal islocated; or the downlink control channel is an enhanced physicaldownlink control channel, the enhanced physical downlink control channelis located in a subframe in which the preamble signal is located, andthe enhanced physical downlink control channel is located in a symbolafter the preamble signal; where the first subframe is the subframe inwhich the preamble signal is located, 0<n<N, and both n and N arenatural numbers.

With reference to the third possible implementation manner, in a fourthpossible implementation manner, that the processing unit determines thetime-domain location of the data in the first subframe according to thepreamble signal received before the downlink control channel includes:the processing unit determines a symbol in which the preamble signal islocated; and the processing unit determines, according to the symbol inwhich the preamble signal is located and a symbol in which the downlinkcontrol channel is located, a symbol in which the data in the firstsubframe is located.

With reference to the third possible implementation manner, in a fifthpossible implementation manner, the location indication information isused to indicate a start symbol m of the data in the first subframe inthe time domain, and that the processing unit determines the time-domainlocation of the data in the first subframe according to the locationindication information in the downlink control channel includes: whenthe downlink control channel is located in the n symbols following thepreamble signal, the processing unit determines that the data in thefirst subframe is between the symbol m and a last symbol of the firstsubframe; or when the downlink control channel is located in the last nsymbols of the subframe in which the preamble signal is located, theprocessing unit determines that the data in the first subframe isbetween the symbol m and a symbol before the downlink control channel.

In a sixth possible implementation manner, the downlink control channelis located in last n symbols of a detected subframe, and the firstsubframe is a subframe in which the downlink control channel is located.

In a seventh possible implementation manner, that the processing unitperforms detection on the downlink control channel to obtain thedownlink control information includes: the processing unit performsdetection on a first downlink control channel and a second downlinkcontrol channel, where the first downlink control channel is located inn symbols at the beginning of a detected subframe, and the seconddownlink control channel is located in last n symbols of the detectedsubframe, and if the downlink control information is obtained in thesecond downlink control channel, the downlink control informationincludes the scheduling indication information, and the first subframeis a subframe in which the downlink control channel is located.

With reference to the sixth or the seventh possible implementationmanner, in an eighth possible implementation manner, the locationindication information is used to indicate a start symbol m of the datain the first subframe in the time domain, and that the processing unitdetermines the time-domain location of the data in the first subframeaccording to the location indication information in the downlink controlchannel includes: the processing unit determines that the data in thefirst subframe is between the symbol m and a symbol before the downlinkcontrol channel.

In a ninth possible implementation manner, that the processing unitperforms detection on the downlink control channel to obtain thedownlink control information includes: the processing unit performsdetection on the downlink control channel to obtain the downlink controlinformation, where the downlink control channel is located in n symbolsat the beginning of a detected subframe; and when the downlink controlinformation includes the location indication information, the processingunit determines that the first subframe is a subframe before a subframein which the downlink control channel is located.

With reference to the ninth possible implementation manner, in a tenthpossible implementation manner, the location indication information isused to indicate a start symbol m of the data in the first subframe inthe time domain, and that the processing unit determines the time-domainlocation of the data in the first subframe according to the locationindication information in the downlink control channel includes: theprocessing unit determines that the data in the first subframe isbetween the symbol m and a last symbol of the first subframe.

With reference to any one of the sixth aspect or the first to the tenthpossible implementation manners, in an eleventh possible implementationmanner, the downlink control information further includes durationindication information, and the duration indication information is usedto indicate available duration of a base station in the unlicensedspectrum.

With reference to the eleventh possible implementation manner, in atwelfth possible implementation manner, the downlink control informationincludes first downlink control information and second downlink controlinformation, the scheduling indication information is in the firstdownlink control information, the duration indication information is inthe second downlink control information, the first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

With reference to any one of the sixth aspect or the first to the fifthpossible implementation manners, in a thirteenth possible implementationmanner, the preamble signal is used to indicate available duration of abase station in the unlicensed spectrum, and at least two differentpreamble signals are corresponding to different duration.

With reference to any one of the eleventh to the thirteenth possibleimplementation manners, in a fourteenth possible implementation manner,the user equipment further includes: perform, by the processing unit inn symbols at the beginning of a second subframe, detection on thedownlink control channel on which the second subframe is scheduled,where the second subframe is in the duration and is after the firstsubframe.

With reference to any one of the sixth aspect or the first to thefourteenth possible implementation manners, in a fifteenth possibleimplementation manner, the preamble signal occupies fixed duration inthe time domain.

In the prior art, a base station sends only a preamble after determininga time-domain interval of available time-frequency resources in anunlicensed spectrum. The preamble in the prior art is used to onlyoccupy a channel, and user equipment cannot receive data or schedulinginformation when the preamble occupies the channel. However, in theembodiments of the present invention, after a base station determines atime-domain interval of available time-frequency resources in anunlicensed spectrum, the base station sends a preamble signal in a firstsubframe in the interval, and then sends downlink control informationand data; or the base station sends downlink control information anddata in a first subframe in the interval. The data is in the firstsubframe. Therefore, at least the data is sent in the first subframe, soas to improve spectrum utilization resource.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention more clearly, the following briefly describes the accompanyingdrawings required for describing the embodiments or the prior art.Apparently, the accompanying drawings in the following description showmerely some embodiments of the present invention, and a person ofordinary skill in the art may still derive other drawings from theseaccompanying drawings without creative efforts.

FIG. 1 is a structural diagram of subframes of an unlicensed carrieraccording to an embodiment of the present invention;

FIG. 2(a) and FIG. 2(b) and FIG. 2c ) are a diagram of a systemaccording to an embodiment of the present invention;

FIG. 3 shows a data sending method according to an embodiment of thepresent invention;

FIG. 4 shows a base station according to an embodiment of the presentinvention;

FIG. 5 shows a data sending method according to an embodiment of thepresent invention;

FIG. 6 shows a base station according to an embodiment of the presentinvention;

FIG. 7 shows a data sending method according to an embodiment of thepresent invention;

FIG. 8 shows user equipment according to an embodiment of the presentinvention;

FIG. 9 is a structural diagram of subframes of an unlicensed carrieraccording to an embodiment of the present invention;

FIG. 10 is a structural diagram of subframes of an unlicensed carrieraccording to an embodiment of the present invention; and

FIG. 11 is a structural diagram of subframes of an unlicensed carrieraccording to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The following clearly and completely describes the technical solutionsin the embodiments of the present invention with reference to theaccompanying drawings in the embodiments of the present invention.Apparently, the described embodiments are some but not all of theembodiments of the present invention. All other embodiments obtained bya person of ordinary skill in the art based on the embodiments of thepresent invention without creative efforts shall fall within theprotection scope of the present invention.

It should be understood that the technical solutions of this applicationmay be applied to various communications systems such as a Code DivisionMultiple Access (CDMA) system, a Wideband Code Division Multiple Access(WCDMA) system, a general packet radio service (GPRS), an LTE system, aLong Term Evolution Advanced (LTE-A) system, and a Universal MobileTelecommunications System (UMTS). This is not limited in embodiments ofthis application. However, for ease of description, the embodiments ofthis application are described by using an LTE system as an example.

FIG. 1 is a structural diagram of subframes of an unlicensed carrier.FIG. 1 shows a licensed primary carrier and an unlicensed secondarycarrier. Frame numbers corresponding to the licensed primary carrier arethe same as frame numbers corresponding to the unlicensed secondarycarrier, and frame boundaries corresponding to the licensed primarycarrier are aligned with frame boundaries corresponding to theunlicensed secondary carrier. After an ECCA process is performed on theunlicensed secondary carrier (certainly, or after a CCA process isperformed, where FIG. 1 is described by using ECCA as an example), datais transmitted by using the unlicensed secondary carrier. Because an endlocation of ECCA performed by a base station on an unlicensed spectrumdoes not coincide with a subframe boundary, a time period from the endof the ECCA process to a subframe 0 is an incomplete subframe, and datacannot be transmitted. In the prior art, sending a preamble in thisstage is proposed. The preamble is used to keep the base stationoccupying a channel resource on which the unlicensed secondary carrieris located. Specifically, in a preamble sending stage, the base stationcannot send scheduling information or data specific to a user.Therefore, user equipment cannot receive data or scheduling informationwhen the preamble occupies the unlicensed secondary carrier. Therefore,scheduling information or data information cannot be sent in a subframein which ECCA is located. This causes a waste of an unlicensed spectrumresource.

FIG. 2(a) and FIG. 2(b) and FIG. 2c ) are a schematic diagram of asystem according to an embodiment of the present invention. The systemapplied in this embodiment of the present invention includes a basestation and UE.

The base station provided in this embodiment of the present inventionmay be a NodeB (NB) in UMTS or an evolved NodeB (eNodeB, eNB) in LTE.The base station communicates with the UE, receives data from the UE,and sends the data to a base station controller or a core networkdevice, or sends the data to a corresponding primary base station, andthen the primary base station sends the data to a base stationcontroller or a core network device.

The UE provided in this embodiment of the present invention may be butis not limited to a mobile station (MS), a mobile terminal, a mobiletelephone, a handset, a portable device, or the like.

For example, as shown in FIG. 2(a), the base station communicates withthe UE by using a licensed primary carrier 1 and an unlicensed secondarycarrier 2, and the base station sends data to a core network. As shownin FIG. 2(b), a base station 1 communicates with the UE by using alicensed primary carrier 1, and a base station 2 communicates with theUE by using a licensed primary carrier 2 and an unlicensed secondarycarrier 3. The base station 2 communicates with the base station 1. Thebase station 1 is a primary base station. Therefore, the base station 1sends data to a core network. As shown in FIG. 2(c), the base stationcommunicates with the UE by using a licensed primary carrier 1 and anunlicensed secondary carrier 2, and the base station sends data to acore network by using a base station controller.

The embodiments of the present invention are based on the foregoingsystem architecture. It should be noted that the embodiments andcharacteristics in the embodiments may be combined with each other ifthere is no conflict.

FIG. 3 shows a data sending method according to an embodiment of thepresent invention, and the method includes the following steps:

Step 31: A base station determines a time-domain interval of availabletime-frequency resources in an unlicensed spectrum. The availabletime-frequency resources are continuous time-frequency resources in atime domain.

Step 32: The base station sends a preamble signal in a first subframe inthe interval. The first subframe is an initial subframe in the interval.

Step 33: The base station sends downlink control information and dataafter sending the preamble signal.

The data is in the first subframe. The downlink control informationincludes scheduling indication information. The scheduling indicationinformation is used to indicate a frequency-domain location of the data.

In the prior art, a base station sends only a preamble after determininga time-domain interval of available time-frequency resources in anunlicensed spectrum. The preamble in the prior art is used to onlyoccupy a channel. Therefore, another base station cannot occupy thechannel. However, user equipment cannot receive data or schedulinginformation when the preamble occupies the channel. However, in thisembodiment of the present invention, after the base station determinesthe time-domain interval of the available time-frequency resources inthe unlicensed spectrum, the base station sends the preamble signal inthe first subframe in the interval, and then sends the downlink controlinformation and the data. The data is in the first subframe. Therefore,at least the data is sent in the first subframe, so as to avoid a wasteof this spectrum resource, and improve spectrum utilization resource.

In an optional embodiment, the preamble signal is a sequence in at leastone preset sequence.

In an optional embodiment, that a base station determines a time-domaininterval of available time-frequency resources in an unlicensed spectrumincludes: the base station may first determine, by means of listening,whether a signal is being sent on a wireless channel on which the firstcarrier is located, and if there is no another device using the wirelesschannel, the base station determines that a signal may be sent by usingthe first carrier. Optionally, a processing period may be required forthe base station to prepare a to-be-sent signal. In order to prevent thechannel being occupied by another device in the processing period, thebase station may transmit specific content with specific power on thechannel in the period. In this case, it is determined that thetime-domain interval of the available time-frequency resources in theunlicensed spectrum starts after the specific content is transmitted.

Optionally, the preamble signal may be specifically a predefinedsequence. The base station sends the preamble signal by using thepredefined sequence, and the user equipment performs detection on thepreamble signal according to the predefined sequence. The predefinedpreamble sequence may be preset in the user equipment or may be receivedfrom the base station by using a message. Optionally, a specific mappingrelationship may exist between the preamble sequence and the unlicensedspectrum, so that the user equipment determines, according to thesequence, a signal including the preamble signal as a signal of aserving cell corresponding to the unlicensed secondary carrier.

Optionally, the first subframe includes N symbols in the time domain.The downlink control channel is located in n symbols following thepreamble signal.

When the downlink control channel is located in the n symbols followingthe preamble signal, the data is in a symbol after the downlink controlchannel.

Optionally, the downlink control channel is located in last n symbols ofthe subframe in which the preamble signal is located.

When the downlink control channel is located in the last n symbols ofthe subframe in which the preamble signal is located, the data is in asymbol between the preamble signal and the downlink control channel.

Optionally, the downlink control channel is an enhanced physicaldownlink control channel (EPDCCH). The enhanced physical downlinkcontrol channel is located in the subframe in which the preamble signalis located, and the enhanced physical downlink control channel islocated in a symbol after the preamble signal, where 0<n<N, and both nand N are natural numbers.

When the downlink control channel is the enhanced physical downlinkcontrol channel, the data is in a symbol after the preamble signal.

In an optional embodiment, the downlink control information furtherincludes location indication information, and the location indicationinformation is used to indicate a start symbol m of the data in thefirst subframe in the time domain.

Optionally, when the downlink control channel is located in the nsymbols following the preamble signal, the data is between the symbol mand a last symbol of the first subframe.

Optionally, when the downlink control channel is located in the last nsymbols of the subframe in which the preamble signal is located, thedata is between the symbol m and a symbol before the downlink controlchannel.

The foregoing m is a natural number.

In an optional embodiment, the preamble signal is in at least one symbolat the beginning of the interval.

In an optional embodiment, the downlink control information furtherincludes duration indication information, and the duration indicationinformation is used to indicate available duration of the base stationin the unlicensed spectrum.

In an optional embodiment, the downlink control information includesfirst downlink control information and second downlink controlinformation. The scheduling indication information is in the firstdownlink control information. The duration indication information is inthe second downlink control information. The first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

In an optional embodiment, the downlink control information or thepreamble message further includes at least one of a cell identifier ofthe unlicensed spectrum, a public land mobile network identifier of theunlicensed spectrum, or a quantity of symbols occupied by the downlinkcontrol information.

In an optional embodiment, the preamble signal is used to indicate theavailable duration of the base station in the unlicensed spectrum, andat least two different preamble signals are corresponding to differentduration.

In an optional embodiment, the base station sends, in n symbols at thebeginning of a second subframe, the downlink control channel on whichthe first subframe is scheduled. The second subframe is in the intervaland is after the first subframe. In an optional embodiment, the downlinkcontrol information further includes a forward scheduling indication.Optionally, the forward scheduling indication may be included in thescheduling indication information. The forward scheduling indication isused by the user equipment to determine the downlink control informationaccording to the forward scheduling indication, and is used to scheduledata in a subframe before a subframe in which the downlink controlinformation is located.

In an optional embodiment, the base station sends, in n symbols at thebeginning of a third subframe, a downlink control channel on which thethird subframe is scheduled. The third subframe is in the interval. Thedownlink control information further includes data symbol indicationinformation, so that the user equipment determines an end location ofthe data in the third subframe according to the symbol indicationinformation. In an optional embodiment, the third subframe is a lastsubframe in the interval.

In an optional embodiment, the preamble signal occupies fixed durationin the time domain.

In an optional embodiment, the downlink control information or thepreamble signal further includes a radio network temporary identifierRNTI. The RNTI is used by the user equipment to receive the downlinkcontrol information according to the RNTI. Optionally, the downlinkcontrol information may further include at least one of duration ofsending the first signal, a cell identifier of the first carrier, apublic land mobile network identifier of the first carrier, or aquantity of symbols occupied by the downlink control information.

FIG. 4 shows a base station according to an embodiment of the presentinvention. The base station may be configured to execute the datasending method provided in the embodiment shown in FIG. 3. The basestation includes a processing unit 401 and a sending unit 402.

The processing unit 401 is configured to determine a time-domaininterval of available time-frequency resources in an unlicensedspectrum. The available time-frequency resources are continuoustime-frequency resources in a time domain.

The sending unit 402 is configured to send a preamble signal in a firstsubframe in the interval. The first subframe is an initial subframe inthe interval.

The sending unit 402 is further configured to send downlink controlinformation and data after sending the preamble signal. The data is inthe first subframe. The downlink control information includes schedulingindication information, and the scheduling indication information isused to indicate a frequency-domain location of the data.

In the prior art, a base station sends only a preamble after determininga time-domain interval of available time-frequency resources in anunlicensed spectrum. The preamble in the prior art is used to onlyoccupy a channel, and user equipment cannot receive data or schedulinginformation when the preamble occupies the channel. However, in thisembodiment of the present invention, after the base station determinesthe time-domain interval of the available time-frequency resources inthe unlicensed spectrum, the base station sends the preamble signal inthe first subframe in the interval, and then sends the downlink controlinformation and the data. The data is in the first subframe. Therefore,at least the data is sent in the first subframe, so as to improvespectrum utilization resource.

In an optional embodiment, the preamble signal sent by the sending unitis a sequence in at least one preset sequence.

Optionally, the preamble signal may be specifically a predefinedsequence. The base station sends the preamble signal by using thepredefined sequence. The user equipment performs detection on thepreamble signal according to the predefined sequence. The predefinedpreamble sequence may be preset in the user equipment or may be receivedfrom the base station by using a message. Optionally, a specific mappingrelationship may exist between the preamble sequence and the unlicensedspectrum, so that the user equipment determines, according to thesequence, a signal including the preamble signal as a signal of aserving cell corresponding to the unlicensed secondary carrier.

In an optional embodiment, the downlink control information is in adownlink control channel, and the first subframe includes N symbols inthe time domain. The downlink control channel is located in n symbolsfollowing the preamble signal, or the downlink control channel islocated in last n symbols of the first subframe, or the downlink controlchannel is an enhanced physical downlink control channel, the enhancedphysical downlink control channel is located in the subframe in whichthe preamble signal is located, and the enhanced physical downlinkcontrol channel is located in a symbol after the preamble signal, where0<n<N, and both n and N are natural numbers.

In an optional embodiment, when the downlink control channel is locatedin the n symbols following the preamble signal, the data is in a symbolafter the downlink control channel. When the downlink control channel islocated in the last n symbols of the subframe in which the preamblesignal is located, the data is in a symbol between the preamble signaland the downlink control channel; or when the downlink control channelis the enhanced physical downlink control channel, the data is in asymbol after the preamble signal.

In an optional embodiment, the downlink control information furtherincludes location indication information, and the location indicationinformation is used to indicate a start symbol m of the data in thefirst subframe in the time domain. When the downlink control channel islocated in the n symbols following the preamble signal, the data isbetween the symbol m and a last symbol of the first subframe.Alternatively, when the downlink control channel is located in the lastn symbols of the subframe in which the preamble signal is located, thedata is between the symbol m and a symbol before the downlink controlchannel. Optionally, m is a natural number.

In an optional embodiment, the preamble signal is in at least one symbolat the beginning of the interval.

In an optional embodiment, the downlink control information furtherincludes duration indication information, and the duration indicationinformation is used to indicate available duration of the base stationin the unlicensed spectrum.

In an optional embodiment, the downlink control information includesfirst downlink control information and second downlink controlinformation. The scheduling indication information is in the firstdownlink control information. The duration indication information is inthe second downlink control information. The first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

In an optional embodiment, the preamble signal is used to indicate theavailable duration in the unlicensed spectrum, and the availableduration is a length of the time-domain interval of the availabletime-frequency resources.

In an optional embodiment, at least two different preamble signalsindicate different duration.

In an optional embodiment, the downlink control information or thepreamble message further includes at least one of a cell identifier ofthe unlicensed spectrum, a public land mobile network identifier of theunlicensed spectrum, or a quantity of symbols occupied by the downlinkcontrol information.

In an optional embodiment, the preamble signal is used to indicate theavailable duration of the base station in the unlicensed spectrum, andat least two different preamble signals are corresponding to differentduration.

In an optional embodiment, the sending unit is further configured tosend, in n symbols at the beginning of a second subframe, the downlinkcontrol channel on which the second subframe is scheduled. The secondsubframe is in the duration and is after the first subframe. In anoptional embodiment, the downlink control information further includes aforward scheduling indication. Optionally, the forward schedulingindication may be included in the scheduling indication information. Theforward scheduling indication is used by the user equipment to determinethe downlink control information according to the forward schedulingindication, and is used to schedule data in a subframe before a subframein which the downlink control information is located.

In an optional embodiment, the preamble signal occupies fixed durationin the time domain.

In an optional embodiment, the downlink control information or thepreamble signal further includes a radio network temporary identifierRNTI. The RNTI is used by the user equipment to receive the downlinkcontrol information according to the RNTI. Optionally, the downlinkcontrol information may further include at least one of duration ofsending the first signal, a cell identifier of a first carrier, a publicland mobile network identifier of the first carrier, or a quantity ofsymbols occupied by the downlink control information.

In an optional implementation manner, the processing unit 401 may be aprocessor. The processor may be specifically a baseband processor, adigital signal processor (DSP), a field programmable gate array (FPGA),or a central processor (CPU). The sending unit 402 may be a transmitter.The sending unit 402 may also be a transceiver. The transmitter or thetransceiver may be a radio frequency circuit or a combination thatincludes the processor and a radio frequency circuit.

In an optional implementation manner, the base station provided in theembodiment shown in FIG. 4 may include a transmitter and a processor.The processor is configured to determine a time-domain interval ofavailable time-frequency resources in an unlicensed spectrum. Theavailable resources are continuous time-frequency resources in a timedomain. The transmitter is configured to send a preamble signal in afirst subframe in the interval. The first subframe is an initialsubframe in the interval. The transmitter is further configured to senddownlink control information and data after the sending unit sends thepreamble signal. The data is in the first subframe. The downlink controlinformation is in a downlink control channel. The downlink controlinformation includes scheduling indication information. The schedulingindication information is used to indicate a frequency-domain locationof the data.

FIG. 5 shows a data sending method according to an embodiment of thepresent invention, and specific steps of the method are as follows:

Step 51: A base station determines a time-domain interval of availabletime-frequency resources in an unlicensed spectrum. The availabletime-frequency resources are continuous time-frequency resources in atime domain.

Step 52: The base station sends downlink control information and data.

The data is in a first subframe, and the first subframe is an initialsubframe in the interval. The downlink control information includesscheduling indication information and location indication information.The scheduling indication information is used to indicate afrequency-domain location of the data. The location indicationinformation is used to indicate a time-domain location of the data.

In the prior art, a base station sends only a preamble after determininga time-domain interval of available time-frequency resources in anunlicensed spectrum. The preamble in the prior art is used to onlyoccupy a channel, and user equipment cannot receive data or schedulinginformation when the preamble occupies the channel. However, in thisembodiment of the present invention, after the base station determinesthe time-domain interval of the available time-frequency resources inthe unlicensed spectrum, the base station sends the downlink controlinformation and the data. The data is in the first subframe. Therefore,at least the data is sent in the first subframe, so as to improvespectrum utilization resource.

In an optional embodiment, that a base station determines a time-domaininterval of available time-frequency resources in an unlicensed spectrumincludes: the base station may first determine, by means of listening,whether a signal is being sent on a wireless channel on which the firstcarrier is located, and if there is no another device using the wirelesschannel, the base station determines that a signal may be sent by usingthe first carrier. Optionally, a processing period may be required forthe base station to prepare a to-be-sent signal. In order to prevent thechannel being occupied by another device in the processing period, thebase station may transmit specific content with specific power on thechannel in the period. In this case, it is determined that thetime-domain interval of the available time-frequency resources in theunlicensed spectrum starts after the specific content is transmitted.

In an optional embodiment, the downlink control information is in adownlink control channel, and the first subframe includes N symbols inthe time domain. The downlink control channel is located in n symbols atthe beginning of a second subframe, and the location indicationinformation is further used to indicate that the first subframe is asubframe before the second subframe. Alternatively, the downlink controlchannel is located in last n symbols of the first subframe, where 0<n<N,and both n and N are natural numbers.

In an optional embodiment, the location indication information is usedto instruct the UE to determine a start symbol m of the data in thefirst subframe in the time domain according to the indicationinformation. When the downlink control channel is located in the nsymbols at the beginning of the second subframe, the data in the firstsubframe is between the symbol m and a last symbol of the firstsubframe. Alternatively, when the downlink control channel is located inthe last n symbols of the first subframe, the data in the first subframeis after the symbol m and before the downlink control channel.Optionally, m is a natural number.

In an optional embodiment, the downlink control information furtherincludes duration indication information, and the duration indicationinformation is used to indicate available duration in the unlicensedspectrum.

In an optional embodiment, the downlink control information includesfirst downlink control information and second downlink controlinformation. The scheduling indication information is in the firstdownlink control information. The duration indication information is inthe second downlink control information. The first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

In an optional embodiment, the base station sends, in the n symbols atthe beginning of the second subframe, the downlink control channel onwhich the first subframe is scheduled. The second subframe is in theduration and is after the first subframe. In an optional embodiment, thedownlink control information further includes a forward schedulingindication. Optionally, the forward scheduling indication may beincluded in the scheduling indication information. The forwardscheduling indication is used by the user equipment to determine thedownlink control information according to the forward schedulingindication, and is used to schedule data in a subframe before a subframein which the downlink control information is located.

In an optional embodiment, the first subframe includes N symbols in thetime domain, and the preamble occupies M symbols. If M=N, data is notsent in the first subframe. Alternatively, if M>N, a part of preambleinformation is sent in the first subframe, and a remaining part ofpreamble information is sent at M−N symbols at the beginning of thesecond subframe after the first subframe. Data is sent in subsequentsymbols of the second subframe. Control information corresponding to thedata is sent in a third subframe after the second subframe.Alternatively, control information and data information are sent insubsequent symbols of the second subframe. The control information maybe after the preamble information or may be in last P symbols of thesecond subframe, and the control information is used to includescheduling information of the data.

In an optional embodiment, the downlink control information or thepreamble signal further includes a radio network temporary identifierRNTI. The RNTI is used by the user equipment to receive the downlinkcontrol information according to the RNTI. Optionally, the downlinkcontrol information may further include at least one of duration ofsending a first signal, a cell identifier of the first carrier, a publicland mobile network identifier of the first carrier, or a quantity ofsymbols occupied by the downlink control information.

In an optional embodiment, the downlink control information may be sentby using a secondary cell corresponding to the unlicensed spectrum, ormay be sent by using a carrier corresponding to a licensed spectrum. Thecarrier corresponding to the licensed spectrum and the secondary carriercorresponding to the unlicensed spectrum are different carriersconfigured for same user equipment.

In an optional embodiment, the downlink control information is sent atthe beginning of the first subframe in the interval, and the datainformation is sent after the control information is sent. If thecontrol information sending ends at a boundary of the first subframe,the data information is not sent in the first subframe.

FIG. 6 shows a base station according to an embodiment of the presentinvention. The base station may be configured to execute the datasending method provided in the embodiment shown in FIG. 5. The basestation includes a processing unit 601 and a sending unit 602.

The processing unit 601 is configured to determine a time-domaininterval of available time-frequency resources in an unlicensedspectrum. The available time-frequency resources are continuoustime-frequency resources in a time domain.

The sending unit 602 is configured to send downlink control informationand data. The data is in a first subframe. The first subframe is aninitial subframe in the interval. The downlink control informationincludes scheduling indication information and location indicationinformation. The scheduling indication information is used to indicate afrequency-domain location of the data. The location indicationinformation is used to indicate a time-domain location of the data.

In the prior art, a base station sends only a preamble after determininga time-domain interval of available time-frequency resources in anunlicensed spectrum. The preamble in the prior art is used to onlyoccupy a channel, and user equipment cannot receive data or schedulinginformation when the preamble occupies the channel. However, in thisembodiment of the present invention, after the base station determinesthe time-domain interval of the available time-frequency resources inthe unlicensed spectrum, the base station sends the downlink controlinformation and the data. The data is in the first subframe. Therefore,at least the data is sent in the first subframe, so as to improvespectrum utilization resource.

In an optional embodiment, the downlink control information is in adownlink control channel, and the first subframe includes N symbols inthe time domain. The downlink control channel is located in n symbols atthe beginning of a second subframe, and the location indicationinformation is further used to indicate that the first subframe is asubframe before the second subframe. Alternatively, the downlink controlchannel is located in last n symbols of the first subframe, where 0<n<N,and both n and N are natural numbers.

In an optional embodiment, the location indication information is usedto indicate a start symbol m of the data in the first subframe in thetime domain. When the downlink control channel is located in the nsymbols at the beginning of the second subframe, the data in the firstsubframe is between the symbol m and a last symbol of the firstsubframe. Alternatively, when the downlink control channel is located inthe last n symbols of the first subframe, the data in the first subframeis after the symbol m and before the downlink control channel.

In an optional embodiment, the downlink control information furtherincludes duration indication information, and the duration indicationinformation is used to indicate available duration in the unlicensedspectrum.

In an optional embodiment, the downlink control information or thepreamble message further includes at least one of a cell identifier ofthe unlicensed spectrum, a public land mobile network identifier of theunlicensed spectrum, or a quantity of symbols occupied by the downlinkcontrol information.

In an optional embodiment, the base station sends, in n symbols at thebeginning of a third subframe, a downlink control channel on which thethird subframe is scheduled. The third subframe is in the interval. Thedownlink control information further includes data symbol indicationinformation, so that the user equipment determines an end location ofthe data in the third subframe according to the symbol indicationinformation. In an optional embodiment, the third subframe is a lastsubframe in the interval.

In an optional embodiment, the downlink control information includesfirst downlink control information and second downlink controlinformation. The scheduling indication information is in the firstdownlink control information. The duration indication information is inthe second downlink control information. The first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

In an optional embodiment, the sending unit 602 is further configured tosend, in the n symbols at the beginning of the second subframe, thedownlink control channel on which the first subframe is scheduled. Thesecond subframe is in the duration and is after the first subframe. Inan optional embodiment, the downlink control information furtherincludes a forward scheduling indication. Optionally, the forwardscheduling indication may be included in the scheduling indicationinformation. The forward scheduling indication is used by the userequipment to determine the downlink control information according to theforward scheduling indication, and is used to schedule data in asubframe before a subframe in which the downlink control information islocated.

In an optional embodiment, the first subframe includes N symbols in thetime domain, and the preamble occupies M symbols. If M=N, data is notsent in the first subframe. Alternatively, if M>N, a part of preambleinformation is sent in the first subframe, and a remaining part ofpreamble information is sent at M−N symbols at the beginning of thesecond subframe after the first subframe. Data is sent in subsequentsymbols of the second subframe. Control information corresponding to thedata is sent in a third subframe after the second subframe.Alternatively, control information and data information are sent insubsequent symbols of the second subframe. The control information maybe after the preamble information or may be in last P symbols of thesecond subframe, and the control information is used to includescheduling information of the data.

In an optional embodiment, the downlink control information may be sentby using a secondary cell corresponding to the unlicensed spectrum, ormay be sent by using a carrier corresponding to a licensed spectrum. Thecarrier corresponding to the licensed spectrum and the secondary carriercorresponding to the unlicensed spectrum are different carriersconfigured for same user equipment.

In an optional embodiment, the downlink control information is sent atthe beginning of the first subframe in the interval, and the datainformation is sent after the control information is sent. If thecontrol information sending ends at a boundary of the first subframe,the data information is not sent in the first subframe.

In an optional embodiment, the downlink control information or thepreamble signal further includes a radio network temporary identifierRNTI. The RNTI is used by the user equipment to receive the downlinkcontrol information according to the RNTI. Optionally, the downlinkcontrol information may further include at least one of duration ofsending a first signal, a cell identifier of a first carrier, a publicland mobile network identifier of the first carrier, or a quantity ofsymbols occupied by the downlink control information.

In an optional implementation manner, the processing unit 601 may be aprocessor. The processor may be specifically a baseband processor, adigital signal processor (DSP), a field programmable gate array (FPGA),or a central processor (CPU). The sending unit 602 may be a transmitter.The sending unit 602 may also be a transceiver. The transmitter or thetransceiver may be a radio frequency circuit or a combination thatincludes the processor and a radio frequency circuit.

In an optional implementation manner, the base station provided in theembodiment shown in FIG. 6 may include a transmitter and a processor.The processor is configured to determine a time-domain interval ofavailable time-frequency resources in an unlicensed spectrum. Theavailable time-frequency resources are continuous time-frequencyresources in a time domain. The transmitter is configured to senddownlink control information and data. The data is in a first subframe,and the first subframe is an initial subframe in the interval. Thedownlink control information is in a downlink control channel. Thedownlink control information includes scheduling indication informationand location indication information. The scheduling indicationinformation is used to indicate a frequency-domain location of the data.The location indication information is used to indicate a time-domainlocation of the data.

FIG. 7 shows a data sending method according to an embodiment of thepresent invention, and specific steps of the method are as follows:

Step 71: User equipment performs detection on a downlink control channelto obtain downlink control information.

The downlink control information includes scheduling indicationinformation. The scheduling indication information is used to indicate afrequency-domain location of scheduled data in a first subframe.Optionally, the downlink control channel is a physical downlink controlchannel (PDCCH).

Step 72: The user equipment determines a time-domain location of data ina first subframe according to location indication information in thedownlink control channel or a preamble signal received in an unlicensedspectrum before the downlink control channel. The location indicationinformation is used to indicate the time-domain location of the data inthe first subframe.

Step 73: The user equipment receives the data in the unlicensed spectrumaccording to the frequency-domain location and the time-domain locationof the data.

In the prior art, user equipment can only determine a frequency-domainlocation of data according to downlink control information, but cannotdetermine a time-domain location of the data. However, in thisembodiment of the present invention, the user equipment determines thetime-domain location of the data in the first subframe according to thelocation indication information in the downlink control channel or thepreamble signal received in the unlicensed spectrum before the downlinkcontrol channel. Therefore, the user equipment may determine thetime-domain location of the data according to the location indicationinformation or the preamble signal, so that utilization of an unlicensedcarrier is more flexible, and spectrum utilization resource is improved.

In an optional embodiment, before the user equipment performs detectionon the downlink control channel to obtain the downlink controlinformation, the method further includes: receiving, by the userequipment, the preamble signal in the unlicensed spectrum. The preamblesignal is a sequence in at least one preset sequence.

Optionally, the preamble signal may be specifically a predefinedsequence. The base station sends the preamble signal by using thepredefined sequence, and the user equipment performs detection on thepreamble signal according to the predefined sequence. The predefinedpreamble sequence may be preset in the user equipment or may be receivedfrom the base station by using a message. Optionally, a specific mappingrelationship may exist between the preamble sequence and the unlicensedspectrum, so that the user equipment determines, according to thesequence, a signal including the preamble signal as a signal of aserving cell corresponding to the unlicensed secondary carrier.

In an optional embodiment, before the user equipment performs detectionon the downlink control channel to obtain the downlink controlinformation, the method further includes: after receiving the preamblesignal, determining, by the user equipment, a location of the downlinkcontrol channel in the unlicensed spectrum according to the preamblesignal.

In an optional embodiment, the subframe includes N symbols in the timedomain. The downlink control channel is located in n symbols followingthe preamble signal. Certainly, the downlink control channel may belocated in n symbols after the preamble signal, and a distance of msymbols exists between the downlink control channel and the preamblesignal, where m is a natural number. The downlink control channel islocated in last n symbols of a subframe in which the preamble signal islocated. Alternatively, the downlink control channel is an enhancedphysical downlink control channel, the enhanced physical downlinkcontrol channel is located in a subframe in which the preamble signal islocated, and the enhanced physical downlink control channel is locatedin a symbol after the preamble signal. The first subframe is thesubframe in which the preamble signal is located, 0<n<N, and both n andN are natural numbers.

In an optional embodiment, the UE performs blind detection on thedownlink control information to determine a symbol location of thedownlink control information, and then determines a symbol location ofthe data part according to the location of the downlink controlinformation. Specifically, for the foregoing manner of sending thedownlink control information, because the user equipment does notdetermine a symbol from which the base station starts to send thedownlink control information, the user equipment needs to performdownlink control information detection on symbols one by one. Thedownlink control information detection is performed on each symbol thatis used as a start symbol of the downlink control information. Once thedownlink control information is detected, the user equipment determinesthe symbol location of the data part according to the downlink controlinformation, and then receives, according to the time-domain symbollocation of the data part and the frequency-domain location included inthe scheduling indication information carried in the downlink controlinformation, the scheduled data indicated in the downlink controlinformation.

In an optional embodiment, that the user equipment determines atime-domain location of data in a first subframe according to a preamblesignal received before the downlink control channel includes: the userequipment determines a symbol in which the preamble signal is located,and the user equipment determines, according to the symbol in which thepreamble signal is located and a symbol in which the downlink controlchannel is located, a symbol in which the data in the first subframe islocated. Specifically, the symbol location occupied by the preamblesignal is determined according to a start symbol location and a lengthof the preamble signal, and the length of the preamble signal is apredefined quantity of symbols. The location of the downlink controlinformation or the location of the data starts at N symbols after thepreamble signal sending ends, and N is a positive integer greater thanor equal to 0. N=0 indicates that the location of the downlink controlinformation or the location of the data starts immediately after thepreamble signal is sent. The UE starts to receive the downlink controlinformation or the data at N symbols after the preamble signal sendingends. The data ends at a subframe end boundary of the subframe in whichthe preamble signal is located.

In an optional embodiment, the location indication information is usedto indicate a start symbol m of the data in the first subframe in thetime domain. That the user equipment determines a time-domain locationof data in a first subframe according to location indication informationin the downlink control channel includes: when the downlink controlchannel is located in the n symbols following the preamble signal, theuser equipment determines that the data in the first subframe is betweenthe symbol m and a last symbol of the first subframe; or when thedownlink control channel is located in the last n symbols of thesubframe in which the preamble signal is located, the user equipmentdetermines that the data in the first subframe is between the symbol mand a symbol before the downlink control channel.

In an optional embodiment, the downlink control channel is located inlast n symbols of a detected subframe, and the first subframe is asubframe in which the downlink control channel is located. Specifically,the user equipment performs downlink control information detectionaccording to a location of the downlink control informationpredetermined at the end of the subframe structure. If the downlinkcontrol information is detected, a start location of the scheduled datais determined, according to the downlink control information, as alocation of starting to send the signal by using a first carrier.

In an optional embodiment, that the user equipment performs detection ona downlink control channel to obtain downlink control informationincludes: the user equipment performs detection on a first downlinkcontrol channel and a second downlink control channel. The firstdownlink control channel is located in n symbols at the beginning of adetected subframe, and the second downlink control channel is located inlast n symbols of the detected subframe. If the downlink controlinformation is obtained in the second downlink control channel, thedownlink control information includes the scheduling indicationinformation, and the first subframe is a subframe in which the downlinkcontrol channel is located. In an optional embodiment, the locationindication information is used to indicate a start symbol m of the datain the first subframe in the time domain. That the user equipmentdetermines a time-domain location of data in a first subframe accordingto location indication information in the downlink control channelincludes: the user equipment determines that the data in the firstsubframe is between the symbol m and a symbol before the downlinkcontrol channel.

In an optional embodiment, that the user equipment performs detection ona downlink control channel to obtain downlink control informationincludes: the user equipment performs detection on the downlink controlchannel to obtain the downlink control information, where the downlinkcontrol channel is located in n symbols at the beginning of a detectedsubframe. When the downlink control information includes the locationindication information, the user equipment determines that the firstsubframe is a subframe before a subframe in which the downlink controlchannel is located.

In an optional embodiment, the user equipment performs detection on thedownlink control channel by using the first carrier or another carrier,to obtain the downlink control information.

In an optional embodiment, the downlink control information furtherincludes a forward scheduling indication. Optionally, the forwardscheduling indication may be included in the scheduling indicationinformation. The forward scheduling indication is used by the userequipment to determine the downlink control information according to theforward scheduling indication, and is used to schedule data in asubframe before a subframe in which the downlink control information islocated.

In an optional embodiment, the location indication information is usedto indicate a start symbol m of the data in the first subframe in thetime domain. That the user equipment determines a time-domain locationof data in a first subframe according to location indication informationin the downlink control channel includes: the user equipment determinesthat the data in the first subframe is between the symbol m and a lastsymbol of the first subframe.

In an optional embodiment, the downlink control information furtherincludes duration indication information, and the duration indicationinformation is used to indicate available duration of the base stationin the unlicensed spectrum. In an optional embodiment, the preamblesignal may also include duration indication information, and theduration indication information is used to indicate available durationof the base station in the unlicensed spectrum. In an optionalembodiment, the downlink control information or the preamble messagefurther includes at least one of a cell identifier of the unlicensedspectrum, a public land mobile network identifier of the unlicensedspectrum, or a quantity of symbols occupied by the downlink controlinformation. The user equipment determines a last subframe in theavailable duration of the base station in the unlicensed spectrum and asymbol length of the last subframe according to the available durationof the base station in the unlicensed spectrum and a symbol length ofthe first subframe. Specifically, for example, the symbol length of thefirst subframe is 5 symbols, and duration of sending the first signal is6 ms. It is assumed that a symbol length of a last subframe of eachframe is 14 symbols. The last subframe is the seventh subframe, and thesymbol length of the last subframe is 9 symbols. The user equipment maydetermine, according to the cell identifier of the unlicensed spectrumand/or the public land mobile network identifier of the unlicensedspectrum, whether a cell in which the preamble signal is currently sentis an unlicensed secondary carrier cell configured for the userequipment.

In an optional embodiment, the downlink control information includesfirst downlink control information and second downlink controlinformation. The scheduling indication information is in the firstdownlink control information. The duration indication information is inthe second downlink control information. The first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

In an optional embodiment, the preamble signal is used to indicateavailable duration of the base station in the unlicensed spectrum, andat least two different preamble signals indicate different duration.

In an optional embodiment, the user equipment detects, in n symbols atthe beginning of a second subframe, the downlink control channel onwhich the second subframe is scheduled. The second subframe is in theduration and is after the first subframe.

In an optional embodiment, the downlink control information furtherincludes a radio network temporary identifier RNTI. The RNTI is used toreceive the downlink control information according to the RNTI.

In an optional embodiment, the preamble signal occupies fixed durationin the time domain.

FIG. 8 shows user equipment according to an embodiment of the presentinvention. The user equipment may be configured to execute the datasending method provided in the embodiment shown in FIG. 7. The userequipment includes a processing unit 801 and a receiving unit 802.

The processing unit 801 is configured to perform detection on a downlinkcontrol channel to obtain downlink control information. The downlinkcontrol information includes scheduling indication information. Thescheduling indication information is used to indicate a frequency-domainlocation of scheduled data in a first subframe. Optionally, the downlinkcontrol channel is a physical downlink control channel (PDCCH).

The processing unit 801 is further configured to determine a time-domainlocation of the data in the first subframe according to locationindication information in the downlink control channel or a preamblesignal received in an unlicensed spectrum before the downlink controlchannel. The location indication information is used to indicate thetime-domain location of the data in the first subframe.

The receiving unit 802 is configured to receive the data in theunlicensed spectrum according to the frequency-domain location and thetime-domain location of the data.

In the prior art, user equipment can only determine a frequency-domainlocation of data according to downlink control information, but cannotdetermine a time-domain location of the data. However, in thisembodiment of the present invention, the user equipment determines thetime-domain location of the data in the first subframe according to thelocation indication information in the downlink control channel or thepreamble signal received in the unlicensed spectrum before the downlinkcontrol channel. Therefore, the user equipment may determine thetime-domain location of the data according to the location indicationinformation or the preamble signal, so that utilization of an unlicensedcarrier is more flexible, and spectrum utilization resource is improved.

In an optional embodiment, before the processing unit 801 performsdetection on the downlink control channel to obtain the downlink controlinformation, the receiving unit 802 further includes: receive thepreamble signal in the unlicensed spectrum. The preamble signal is asequence in at least one preset sequence.

Optionally, the preamble signal may be specifically a predefinedsequence. The base station sends the preamble signal by using thepredefined sequence, and the user equipment performs detection on thepreamble signal according to the predefined sequence. The predefinedpreamble sequence may be preset in the user equipment or may be receivedfrom the base station by using a message. Optionally, a specific mappingrelationship may exist between the preamble sequence and the unlicensedcarrier, so that the user equipment determines, according to thesequence, a signal including the preamble signal as a signal of aserving cell corresponding to the unlicensed secondary carrier.

In an optional embodiment, before the processing unit 801 performsdetection on the downlink control channel to obtain the downlink controlinformation, the processing unit 801 further includes: after receivingthe preamble signal, determine, by the processing unit, a location ofthe downlink control channel in the unlicensed spectrum according to thepreamble signal.

In an optional embodiment, the subframe includes N symbols in the timedomain. The downlink control channel is located in n symbols followingthe preamble signal. Certainly, the downlink control channel may belocated in n symbols after the preamble signal, and a distance of msymbols exists between the downlink control channel and the preamblesignal, where m is a natural number. The downlink control channel islocated in last n symbols of a subframe in which the preamble signal islocated. Alternatively, the downlink control channel is an enhancedphysical downlink control channel, the enhanced physical downlinkcontrol channel is located in a subframe in which the preamble signal islocated, and the enhanced physical downlink control channel is locatedin a symbol after the preamble signal. The first subframe is thesubframe in which the preamble signal is located, 0<n<N, and both n andN are natural numbers.

In an optional embodiment, that the processing unit 801 determines atime-domain location of the data in the first subframe according to apreamble signal received before the downlink control channel includes:the processing unit 801 determines a symbol in which the preamble signalis located; and the processing unit 801 determines, according to thesymbol in which the preamble signal is located and a symbol in which thedownlink control channel is located, a symbol in which the data in thefirst subframe is located.

In an optional embodiment, the UE performs blind detection on thedownlink control information to determine a symbol location of thedownlink control information, and then determines a symbol location ofthe data part according to the location of the downlink controlinformation. Specifically, for the foregoing manner of sending thedownlink control information, because the UE does not determine a symbolfrom which the base station starts to send the downlink controlinformation, the user equipment needs to perform downlink controlinformation detection on symbols one by one. The downlink controlinformation detection is performed on each symbol that is used as astart symbol of the downlink control information. Once the downlinkcontrol information is detected, the user equipment determines thesymbol location of the data part according to the downlink controlinformation, and then receives, according to the time-domain symbollocation of the data part and the frequency-domain location included inthe scheduling indication information carried in the downlink controlinformation, the scheduled data indicated in the downlink controlinformation.

In an optional embodiment, that the user equipment determines atime-domain location of the data in the first subframe according to apreamble signal received before the downlink control channel includes:the user equipment determines a symbol in which the preamble signal islocated, and the user equipment determines, according to the symbol inwhich the preamble signal is located and a symbol in which the downlinkcontrol channel is located, a symbol in which the data in the firstsubframe is located. Specifically, the symbol location occupied by thepreamble signal is determined according to a start symbol location and alength of the preamble signal, and the length of the preamble signal isa predefined quantity of symbols. The location of the downlink controlinformation or the location of the data starts at N symbols after thepreamble signal sending ends, and N is a positive integer greater thanor equal to 0. N=0 indicates that the location of the downlink controlinformation or the location of the data starts immediately after thepreamble signal is sent. The UE starts to receive the downlink controlinformation or the data at N symbols after the preamble signal sendingends. The data ends at a subframe end boundary of the subframe in whichthe preamble signal is located.

In an optional embodiment, the preamble signal may be further used bythe user equipment to determine that the signal sent by using theunlicensed carrier is sent to a cell in which the user equipment islocated.

In an optional embodiment, the location indication information is usedto indicate a start symbol m of the data in the first subframe in thetime domain. That the processing unit 801 determines a time-domainlocation of the data in the first subframe according to locationindication information in the downlink control channel includes: whenthe downlink control channel is located in the n symbols following thepreamble signal, the processing unit 801 determines that the data in thefirst subframe is between the symbol m and a last symbol of the firstsubframe; or when the downlink control channel is located in the last nsymbols of the subframe in which the preamble signal is located, theprocessing unit 801 determines that the data in the first subframe isbetween the symbol m and a symbol before the downlink control channel.

In an optional embodiment, the downlink control channel is located inlast n symbols of a detected subframe, and the first subframe is asubframe in which the downlink control channel is located. Specifically,the user equipment performs downlink control information detectionaccording to a location of the downlink control informationpredetermined at the end of the subframe structure. If the downlinkcontrol information is detected, a start location of the scheduled datais determined, according to the downlink control information, as alocation of starting to send the signal by using a first carrier.

In an optional embodiment, that the processing unit 801 performsdetection on a downlink control channel to obtain downlink controlinformation includes: the processing unit 801 performs detection on afirst downlink control channel and a second downlink control channel.The first downlink control channel is located in n symbols at thebeginning of a detected subframe, and the second downlink controlchannel is located in last n symbols of the detected subframe. If thedownlink control information is obtained in the second downlink controlchannel, the downlink control information includes the schedulingindication information, and the first subframe is a subframe in whichthe downlink control channel is located.

In an optional embodiment, the location indication information is usedto indicate a start symbol m of the data in the first subframe in thetime domain. That the processing unit 801 determines a time-domainlocation of the data in the first subframe according to locationindication information in the downlink control channel includes: theprocessing unit 801 determines that the data in the first subframe isbetween the symbol m and a symbol before the downlink control channel.

In an optional embodiment, that the processing unit 801 performsdetection on a downlink control channel to obtain downlink controlinformation includes: the processing unit 801 performs detection on thedownlink control channel to obtain the downlink control information,where the downlink control channel is located in n symbols at thebeginning of a detected subframe; and when the downlink controlinformation includes the location indication information, the processingunit 801 determines that the first subframe is a subframe before asubframe in which the downlink control channel is located.

In an optional embodiment, the location indication information is usedto indicate a start symbol m of the data in the first subframe in thetime domain. That the processing unit 801 determines a time-domainlocation of the data in the first subframe according to locationindication information in the downlink control channel includes: theprocessing unit 801 determines that the data in the first subframe isbetween the symbol m and a last symbol of the first subframe.

In an optional embodiment, the downlink control information furtherincludes duration indication information, and the duration indicationinformation is used to indicate available duration of the base stationin the unlicensed spectrum. In an optional embodiment, the downlinkcontrol information or the preamble message further includes at leastone of a cell identifier of the unlicensed spectrum, a public landmobile network identifier of the unlicensed spectrum, or a quantity ofsymbols occupied by the downlink control information. The user equipmentdetermines a last subframe in the available duration of the base stationin the unlicensed spectrum and a symbol length of the last subframeaccording to the available duration of the base station in theunlicensed spectrum and a symbol length of the first subframe.Specifically, for example, the symbol length of the first subframe is 5symbols, and duration of sending the first signal is 6 ms. It is assumedthat a symbol length of a last subframe of each frame is 14 symbols. Thelast subframe is the seventh subframe, and the symbol length of the lastsubframe is 9 symbols. The user equipment may determine, according tothe cell identifier of the unlicensed spectrum and/or the public landmobile network identifier of the unlicensed spectrum, whether a cell inwhich the preamble signal is currently sent is an unlicensed secondarycarrier cell configured for the user equipment.

In an optional embodiment, the downlink control information includesfirst downlink control information and second downlink controlinformation. The scheduling indication information is in the firstdownlink control information. The duration indication information is inthe second downlink control information. The first downlink controlinformation is in a user-specific search interval, and the seconddownlink control information is in a public search interval.

In an optional embodiment, the preamble signal is used to indicateavailable duration of the base station in the unlicensed spectrum, andat least two different preamble signals are corresponding to differentduration.

In an optional embodiment, the processing unit 801 performs, in nsymbols at the beginning of a second subframe, detection on the downlinkcontrol channel on which the second subframe is scheduled. The secondsubframe is in the duration and is after the first subframe.

In an optional embodiment, the downlink control information furtherincludes a radio network temporary identifier RNTI. The RNTI is used toreceive the downlink control information according to the RNTI.

In an optional embodiment, the preamble signal occupies fixed durationin the time domain.

In an optional implementation manner, the processing unit 801 may be aprocessor. The processor may be specifically a baseband processor, adigital signal processor (DSP), a field programmable gate array (FPGA),or a central processor (CPU). The receiving unit 802 may be a receiver.The receiving unit 802 may also be a transceiver. The receiver or thetransceiver may be a radio frequency circuit or a combination thatincludes the processor and a radio frequency circuit.

In an optional implementation manner, the user equipment provided in theembodiment shown in FIG. 8 may include a receiver and a processor. Theprocessor is configured to perform detection on a downlink controlchannel to obtain downlink control information. The downlink controlinformation includes scheduling indication information. The schedulingindication information is used to indicate a frequency-domain locationof scheduled data in a first subframe. The processor is furtherconfigured to determine a time-domain location of the data in the firstsubframe according to location indication information in the downlinkcontrol channel or a preamble signal received in an unlicensed spectrumbefore the downlink control channel. The location indication informationis used to indicate the time-domain location of the data in the firstsubframe. The receiver is configured to receive the data in theunlicensed spectrum according to the frequency-domain location and thetime-domain location of the data.

The following describes the embodiments of the present invention in moredetail with reference to specific examples.

FIG. 9 is a structural diagram of subframes of an unlicensed carrieraccording to an embodiment of the present invention. As shown in FIG. 9,signal sending may start from a symbol at the middle of a subframe 2 byusing an unlicensed carrier.

Specifically, a base station may determine, by means of CCA or ECCA,that sending a signal to UE may start from a first symbol of thesubframe 2 of a first carrier.

The signal may include one or more of a preamble signal, downlinkcontrol information, or data. Time of occupying the unlicensed spectrumby the base station is limited, for example, may be 6 ms. Certainly, thetime may be another value. This is not limited in this embodiment of thepresent invention. In this case, the base station may send the signal induration of 6 ms. Specifically, the base station starts to send thepreamble signal from the first symbol of the subframe 2. The preamblesignal may occupy multiple symbols of the subframe 2. In this embodimentof the present invention, the preamble signal may be used to determine atime-domain location of the data. After the preamble signal is sent, thedownlink control information and/or the data may be sent at a symbol ofthe subframe 2. Optionally, specifically, as shown in FIG. 9(a), thedownlink control information is sent on a PDCCH, and the data is sent ona PDSCH.

For example, if the first symbol is a symbol 3 of the subframe 2, thebase station sends the preamble at the symbol 3, sends the PDCCH at asymbol 4, and starts to send the data from a symbol 5 until a lastsymbol. Starting from a second subframe, the PDCCH is sent at firstseveral symbols of each subframe, and the data is sent at subsequentsymbols. For a last subframe, the PDCCH is sent at first several symbolsof the last subframe, and the data is sent at subsequent symbols.

For another example, if the first symbol is a symbol 3 of the subframe2, the base station sends the preamble at the symbol 3, starts to sendthe data from a symbol 4 until a symbol before a last symbol, and sendsthe PDCCH at the last symbol of the subframe 2. Starting from a secondsubframe, the PDCCH is sent at first several symbols of each subframe,and the data is sent at subsequent symbols. For a last subframe, thePDCCH is sent at first several symbols of the last subframe, and thedata is sent at subsequent symbols.

The data is sent after the downlink control information is sent. In anoptional embodiment, the base station starts to send the preamble signalfrom the first symbol of the subframe 2. The data is sent after thepreamble signal is sent. The downlink control information is sent afterthe data is sent.

The subframe 2 in this embodiment is a first subframe in a time-domaininterval of time-frequency resources that are in an unlicensed spectrumand are available to the base station.

In an optional embodiment, specifically, as shown in FIG. 9(b), thedownlink control information is sent on an EPDCCH, and the data is senton a PDSCH. For a case in which the downlink control information is senton the EPDCCH, the preamble signal is sent at first two availablesymbols of the subframe 2, that is, the base station sends the preamblesignal at a first symbol and a second symbol of the first subframe inthe time-domain interval of the time-frequency resources that are in theunlicensed spectrum and are available to the base station. The downlinkcontrol information sending starts at a predetermined symbol. If aserial number of the predetermined symbol is greater than a serialnumber of the second symbol, the downlink control information and thedata are sent at each symbol from the predetermined symbol to a lastsymbol of the first subframe. For example, the preamble signal sendingends at a symbol N of the first subframe, but a predetermined sendingstart location of the downlink control information sent on the EPDCCH isa symbol P. The sending start location of the downlink controlinformation may be configured for user equipment by using a network, ormay be stored in user equipment in a predetermining manner. If P>N, thedownlink control information sending starts from the symbol P. If P<N,the downlink control information sending starts from a symbol N+1.

Optionally, after the preamble signal is sent, the downlink controlinformation is not immediately sent. The downlink control informationmay be sent after several symbols.

In the embodiment shown in FIG. 9, because the signal at least occupiesall symbols from the first symbol of the subframe 2 to a last symbol ofthe subframe 2, utilization of an unlicensed carrier is improved.

Optionally, the preamble signal is used by user equipment to determine astart location of the signal in a time domain. The preamble signalincludes a preamble sequence. The user equipment may determine, bydetecting the preamble sequence, that the signal sent by using theunlicensed carrier is sent to a cell to which the user equipmentbelongs. Optionally, the preamble signal may further carry at least oneof duration of the signal, a cell identifier of the unlicensed carrier,a public land mobile network identifier of the unlicensed carrier, or aquantity of symbols occupied by the downlink control information.

For the subframe 2, the user equipment determines, by detecting thepreamble signal sent by the base station, that the signal sent by usingthe unlicensed carrier is sent to the cell to which the user equipmentbelongs. Then, the user equipment receives the downlink controlinformation and the data subsequent to the preamble signal, and reads,according to the downlink control information, the scheduled dataindicated in the downlink control information.

For the signal receiving at middle subframes, because subframessubsequent to the first subframe are complete subframes other than alast subframe occupied by the signal, the base station may send thedownlink control information and the data according to the prior art,and the user equipment may receive the downlink control information andthe data according to the prior art. The downlink control informationmay be obtained from the PDCCH or the EPDCCH of the first carrier, ormay be obtained from a PDCCH or an E-PDCCH of another carrier.

For the signal receiving at a last subframe occupied by the signal, ifthe user equipment obtains, from the preamble signal, available durationof the base station in the unlicensed carrier, the user equipment maylearn of a last subframe and a last symbol of the last subframeaccording to a symbol of a start moment for sending the signal.

Specifically, as shown in FIG. 9, if the user equipment learns,according to the preamble signal, that the duration of the signal is 6ms and that a start symbol for sending the signal is a fifth symbol ofthe subframe 2, five complete subframes and two incomplete subframesexist in this transmission, and specifically are the symbol 5 to asymbol 14 of the subframe 2, a subframe 3 to a subframe 7, and a firstsymbol to a fourth symbol of a subframe 8. The user equipment maydetermine that the subframe 8 is an end subframe, and a length of totalsymbols occupied by the first signal in the subframe 8 is four symbols.The UE may receive the downlink control information and the data at thelast symbol according to the information. For example, if the downlinkcontrol information is received on the PDCCH, after subtracting symbolsoccupied by the downlink control information, the user equipmentreceives the data at remaining symbols, in the four symbols of thesubframe 8, that are used as the PDSCH on which the data is located. Ifthe downlink control information is received on the EPDCCH, the userequipment uses the fourth symbol of the subframe 8 as an end symbol ofreceiving the downlink control information on the EPDCCH, and receivesthe data at the first four symbols of the subframe 8 that are used asthe PDSCH on which the data is located.

For the signal receiving at the last subframe occupied by the signal, inan optional embodiment, the base station adds location information of asymbol occupied by the data into the downlink control information, andthe user equipment determines a location of the data according to thelocation information, and receives the data on the PDSCH according tothe location. For example, if an end symbol of data sending is carriedin the downlink control information, the user equipment determines anend location of the data on the PDSCH according to the end symbol andreceives the data.

The preamble signal described in this embodiment of the presentinvention is not a preamble signal sent by a base station after CCA orECCA in the prior art. In the prior art, the preamble signal is used toonly occupy a channel, to prevent the channel being occupied by anotherbase station. However, in this embodiment of the present invention, userequipment may determine a time-domain location of data in a firstsubframe according to the preamble signal. The preamble signal is asequence in at least one preset sequence. The user equipment maydetermine duration of the first signal according to different presetsequences. After receiving the preamble signal, the user equipmentdetermines a location of a downlink control channel in an unlicensedspectrum according to the preamble signal. The user equipment does notneed to cache a large quantity of signals to detect downlink controlinformation. After receiving the preamble signal, the user equipment maydetermine the location of the downlink control channel and obtain thedownlink control information. In this case, the user equipment onlyneeds to perform downlink control information detection in limitedsymbols, to identify the downlink control information specific to theuser equipment, and then reads the data according to schedulingindication information in the downlink control information.

FIG. 10 is a structural diagram of subframes of an unlicensed carrieraccording to an embodiment of the present invention. A structure of thesubframes of the unlicensed carrier shown in FIG. 10 is basically thesame as the structure of the subframes of the unlicensed carrier shownin FIG. 9, and same content is not repeatedly described herein. Adifference between the embodiment shown in FIG. 10 and the embodimentshown in FIG. 9 lies in that a first signal in the embodiment shown inFIG. 10 does not include a preamble signal, but a first signal in theembodiment shown in FIG. 9 includes a preamble signal.

A base station starts to send a first signal from a first symbol of asubframe. The first signal includes downlink control information anddata. For example, duration of the first signal is 6 ms. Specifically,the base station starts to send the downlink control information fromthe first symbol of the subframe. Optionally, the downlink controlinformation is sent on a PDCCH, and the data is sent on a PDSCH.Specifically, as shown in FIG. 10(a), the downlink control informationincludes an RNTI. The RNTI is used by user equipment to determine thatthe downlink control information is sent to the user equipment. The datais sent after the downlink control information is sent.

In an optional embodiment, the base station sends the downlink controlinformation and the data on each symbol from the first symbol of thesubframe to the subframe. Specifically, as shown in FIG. 10(b), thedownlink control information includes a radio network temporaryidentifier (RNTI). The RNTI is used by user equipment to determine thatthe downlink control information is sent to the user equipment.

In an optional embodiment, after the preamble signal is sent, thedownlink control information is not immediately sent. The downlinkcontrol information may be sent after several symbols.

When receiving the signal, the user equipment cannot learn of a symbolat which the base station starts to send the downlink controlinformation. Therefore, the base station needs to perform detection onsymbols one by one, and the detection starts from the first symbol ofthe subframe. Once the downlink control information that belongs to theuser equipment is detected, the user equipment reads, according to thedownlink control information, the scheduled data indicated in thedownlink control information.

FIG. 11 is a structural diagram of subframes of an unlicensed carrieraccording to an embodiment of the present invention. As shown in FIG.11, signal sending may start from a symbol at the middle of a secondsubframe by using an unlicensed carrier.

Optionally, a base station determines, by means of CCA or ECCA, thatsignal sending may start from a first symbol of the subframe 2 by usinga first carrier.

The base station starts to send the signal from the first symbol of thesubframe 2. The signal includes downlink control information and data.For example, duration of the signal is 6 ms.

In an optional embodiment, the base station starts to send the data fromthe first symbol of the subframe 2, and sends the downlink controlinformation after the data is sent. The downlink control information issent at last N symbols of the subframe 2, and N is a natural number.Specifically, as shown in FIG. 11(a), the downlink control informationis sent at several symbols at the end of a first subframe, and thedownlink control information is sent on a PDCCH.

In an optional embodiment, the base station sends the data at at leastone symbol from the first symbol of the subframe 2 to a last symbol ofthe subframe 2, and sends the downlink control information at a subframefollowing the subframe 2. Specifically, as shown in FIG. 11(b), thedownlink control information is sent at a subframe 3 following thesubframe 2. The downlink control information described in the embodimentshown in FIG. 11(b) includes a forward scheduling indication. Theforward scheduling indication is used by user equipment to determine,according to the forward scheduling indication, that the downlinkcontrol information is used to schedule data in a subframe before asubframe in which the downlink control information is located.

In the embodiment shown in FIG. 11, because the signal at least occupiesall symbols from the first symbol of the subframe 2 to a last symbol ofthe subframe 2, utilization of an unlicensed carrier is improved.

In an optional embodiment, the downlink control information described inembodiments shown in FIG. 11(a) and FIG. 11(b) further includes a radionetwork temporary identifier RNTI. The RNTI is used by the userequipment to receive the downlink control information according to theRNTI. Optionally, the downlink control information may further includeat least one of duration of sending the first signal, a cell identifierof the first carrier, a public land mobile network identifier of thefirst carrier, or a quantity of symbols occupied by the downlink controlinformation.

For the signal receiving at middle subframes, because subframessubsequent to the first subframe are complete subframes other than alast subframe occupied by the first signal, the base station may sendthe downlink control information and the data according to the priorart, and the user equipment may receive the downlink control informationand the data according to the prior art. The downlink controlinformation may be obtained from the PDCCH or an EPDCCH of the firstcarrier, or may be obtained from a PDCCH or an E-PDCCH of anothercarrier.

In this embodiment, because the downlink control information is sent atlast N symbols of a subframe (as shown in FIG. 11a ) or is sent at firstN symbols of a subframe (as shown in FIG. 11b ), when receiving thefirst signal, the user equipment cannot learn of a specific location ofsending the downlink control information in a subframe by the basestation. However, for the location of the downlink control informationin this embodiment, there are only two cases, that is, the downlinkcontrol information is sent at last N symbols of a subframe, or thedownlink control information is sent at first N symbols of a subframe.Certainly, the downlink control information can only be sent at last Nsymbols or first N symbol of a same subframe, but cannot besimultaneously sent at the last N symbols and the first N symbols.

The user equipment performs detection on first N symbols of a subframe.If the downlink control information is detected, the user equipmentreads, according to the downlink control information, the scheduled dataindicated in the downlink control information. The downlink controlinformation detected in the first N symbols may be used to schedule thedata in the subframe in which the downlink control information islocated, or may be used to schedule data in a subframe before thesubframe in which the downlink control information is located. When thedownlink control information is used to schedule the data in thesubframe before the subframe in which the downlink control informationis located, the user equipment first needs to cache the data in thesubframe before the subframe in which the downlink control informationis located. If the downlink control information is not detected in thefirst N symbols, the user equipment detects the downlink controlinformation in last N symbols. Before detecting the downlink controlinformation in the last N symbols, the user equipment needs to cache thedata sent by the base station. After detecting the downlink controlinformation in the last N symbols, the user equipment reads, accordingto the downlink control information, the scheduled data indicated in thedownlink control information. Because the user equipment needs to onlydetect downlink control information in first N symbols or last N symbolsof a subframe, compared with detection performed on symbols of asubframe one by one, energy consumption of user equipment may bereduced, and a running speed of the user equipment may be increased.

In the embodiment shown in FIG. 11(a), when receiving the first signal,the user equipment first caches the first signal. Then the userequipment determines, according to the RNTI, the downlink controlinformation corresponding to the user equipment, receives the downlinkcontrol information, and reads, according to the downlink controlinformation, the scheduled data indicated in the downlink controlinformation.

For example, if the user equipment detects that downlink controlinformation corresponding to a predetermined RNTI is sent at last Nsymbols of the subframe 2, and the downlink control informationindicates that data in the current subframe occupies N symbols, whenreceiving the data, the user equipment only receives the datacorresponding to N symbols before the symbols occupied by the downlinkcontrol information.

If the user equipment detects that downlink control informationcorresponding to a predetermined RNTI is sent at first several symbolsof a current subframe in which the downlink control information islocated, and the downlink control information indicates that data in thecurrent subframe occupies N symbols, when receiving the data, the userequipment only receives the data corresponding to N symbols after thesymbols occupied by the downlink control information.

Optionally, if the downlink control information indicates that thesignal occupies duration of D milliseconds, in subsequent D−1milliseconds, the user equipment does not detect the downlink controlinformation in the last N symbols of the subframe, but only detects thedownlink control information in first several symbols of the subframe.

In the embodiment shown in FIG. 11(b), the user equipment detectsdownlink control information corresponding to a predetermined RNTI. Thedownlink control information may be received from a PDCCH of a subframe3 following a subframe 2 of the signal shown in FIG. 11(b). In anoptional embodiment, the downlink control information may also bereceived from a PDCCH of another licensed carrier or another unlicensedcarrier. Then, the user equipment reads data in a first subframe of thefirst carrier according to the downlink control information.

Optionally, the user equipment may determine, according to symbolinformation of data indicated in the downlink control information, aquantity of symbols occupied by the data in the subframe 2. Optionally,the UE determines the downlink control information according to aforward scheduling indication in the downlink control information, toschedule data in a subframe before a subframe in which the downlinkcontrol information is located.

The embodiments of the present invention and characteristics in theembodiments may be combined with each other if there is no conflict.

The foregoing descriptions are merely specific implementation manners ofthe present invention, but are not intended to limit the protectionscope of the present invention. Any variation or replacement readilyfigured out by a person skilled in the art within the technical scopedisclosed in the present invention shall fall within the protectionscope of the present invention. Therefore, the protection scope of thepresent invention shall be subject to the protection scope of theclaims.

What is claimed is:
 1. A data sending method, comprising: determining,by a base station, a time-domain interval of available time-frequencyresources in an unlicensed spectrum, wherein the availabletime-frequency resources are continuous time-frequency resources in atime domain; and sending, by the base station, downlink controlinformation and data, wherein the data is in a first subframe, the firstsubframe is an initial subframe in the interval, the downlink controlinformation comprises scheduling indication information, locationindication information, and data symbol indication information, thescheduling indication information is used to indicate a frequency-domainlocation of the data, and the location indication information is used toindicate a time-domain location of the data, the data symbol indicationinformation is used to indicate an end location of the data in the thirdsubframe, the third subframe is a last subframe in the time-domaininterval of available time-frequency resources in an unlicensedspectrum.
 2. The method according to claim 1, the method furthercomprises, sending, by the base station, the downlink controlinformation by using a secondary cell corresponding to the unlicensedspectrum.
 3. The method according to claim 1, the method furthercomprises, the downlink control information further comprises a radionetwork temporary identifier (RNTI), the RNTI is used by a userequipment to receive the downlink control information according to theRNTI.
 4. A base station, comprising: a processing unit, configured todetermine a time-domain interval of available time-frequency resourcesin an unlicensed spectrum, wherein the available time-frequencyresources are continuous time-frequency resources in a time domain; anda sending unit, configured to send downlink control information anddata, wherein the data is in a first subframe, the first subframe is aninitial subframe in the interval, the downlink control informationcomprises scheduling indication information, location indicationinformation, and data symbol indication information, the schedulingindication information is used to indicate a frequency-domain locationof the data, and the location indication information is used to indicatea time-domain location of the data, the data symbol indicationinformation is used to indicate an end location of the data in the thirdsubframe, the third subframe is a last subframe in the time-domaininterval of available time-frequency resources in an unlicensedspectrum.
 5. The base station according to claim 4, wherein the sendingunit further configured to send the downlink control information byusing a secondary cell corresponding to the unlicensed spectrum.
 6. Thebase station according to claim 4, the method further comprises, thedownlink control information further comprises a radio network temporaryidentifier (RNTI), the RNTI is used by a user equipment to receive thedownlink control information according to the RNTI.
 7. A data receivingmethod, comprising: performing, by user equipment, detection on adownlink control channel to obtain downlink control information, whereinthe downlink control information comprises scheduling indicationinformation and location indication information, and the schedulingindication information is used to indicate a frequency-domain locationof scheduled data in a first subframe; determining, by the userequipment, a time-domain location of the data in the first subframeaccording to location indication information in the downlink controlinformation or a preamble signal received in an unlicensed spectrumbefore the downlink control channel, wherein the location indicationinformation is used to indicate the time-domain location of the data inthe first subframe; and receiving, by the user equipment, the data inthe unlicensed spectrum according to the frequency-domain location andthe time-domain location of the data.
 8. The method according to claim7, wherein the downlink control information comprises data symbolindication information, the method further comprises: determining, bythe user equipment, an end location of the data in the first subframeaccording to the data symbol indication information.
 9. The methodaccording to claim 7, wherein the first subframe is a last subframe inthe time-domain interval of available time-frequency resources in anunlicensed spectrum.
 10. The method according to claim 7, the methodfurther comprises: receiving, by the user equipment, the downlinkcontrol information by using a secondary cell corresponding to theunlicensed spectrum.
 11. The method according to claim 7, the methodfurther comprises: the downlink control information further comprises aradio network temporary identifier (RNTI), the RNTI is used by the userequipment to receive the downlink control information according to theRNTI.
 12. User equipment, comprising: a processor, configured to performdetection on a downlink control channel to obtain downlink controlinformation, wherein the downlink control information comprisesscheduling indication information and location indication information,and the scheduling indication information is used to indicate afrequency-domain location of scheduled data in a first subframe, whereinthe processor is further configured to determine a time-domain locationof the data in the first subframe according to location indicationinformation in the downlink control information or a preamble signalreceived in an unlicensed spectrum before the downlink control channel,wherein the location indication information is used to indicate thetime-domain location of the data in the first subframe; and a receivingunit, configured to receive the data in the unlicensed spectrumaccording to the frequency-domain location and the time-domain locationof the data.
 13. The user equipment according to claim 12, wherein thedownlink control information comprises data symbol indicationinformation, the processor is further configured to determine an endlocation of the data in the first subframe according to the data symbolindication information.
 14. The user equipment according to claim 12,wherein the first subframe is a last subframe in the time-domaininterval of available time-frequency resources in an unlicensedspectrum.
 15. The user equipment according to claim 12, the methodfurther comprises: the receiving unit, further configured to receive thedownlink control information by using a secondary cell corresponding tothe unlicensed spectrum.
 16. The user equipment according to claim 12,the method further comprises: the downlink control information furthercomprises a radio network temporary identifier (RNTI), the RNTI is usedby the user equipment to receive the downlink control informationaccording to the RNTI.